On Tuesday, the university fired O'Brien because he admitted he gave a recruit $6,000 five years ago -- not long after he ran off
several problem players left over from the previous coach.

"I am troubled that a rule was admittedly violated and it took us five years to find out about it," said athletic director Andy
Geiger, who frequently championed the honesty of his basketball coach as the Buckeyes struggled through a 14-16 season last year.

Geiger said he was stunned when he found out about what he called serious violations in the basketball program.

NCAA spokeswoman Kay Hawes said the governing body is investigating O'Brien and the Ohio State basketball program.
O'Brien's contract, which paid him more than $850,000 per year, specifies the university can fire him for any NCAA violations.

His firing was took effect immediately. Geiger said assistant Rick Boyages would take over on an interim basis during the search
for a new coach. O'Brien was 133-88 in seven years at Ohio State.

Xavier's Thad Matta, coming off an Elite Eight appearance, and North Carolina State's Herb Sendek, who once coached at nearby Miami of Ohio, will be sought after by Geiger, sources told ESPN.com. A clamoring to bring Buckeye alumnus Bob Knight back into the fold is also expected.

Boyages was a former assistant under O'Brien at Boston College and was in his second stint under O'Brien at Ohio State. Boyages was head coach William & Mary prior to the 2003-04 season.

In a statement released through his lawyer, O'Brien did not dispute he helped potential recruit Aleksandar Radojevic.

"I am advised that my firing is because I was asked to and tried to give assistance to a young man's family who was in dire
financial straits,'' said O'Brien, who did not return phone messages left at his home and office. "The assistance in no way
influenced the young man in his decision to attend OSU and, indeed,
the young man did not enroll at OSU."

O'Brien's lawyer, James Zeszutek, told ESPN.com that O'Brien received a letter by hand from the university stating that he was being fired for alleged violations of NCAA bylaws. Zeszutek also said O'Brien expected to go through an NCAA appeals process to contest his dismissal.

Geiger would not say whether the money was O'Brien's or came from another source.

"My understanding is it was not the school's (money)," Geiger said.

Geiger said O'Brien indicated he gave the money to Radojevic because the player's father had died, his mother was unable to work and he had three siblings.

Radojevic, a 7-foot-3 center, played in his native Yugoslavia and was recruited and signed by O'Brien. Before he attended a class
or wore an Ohio State uniform, however, the NCAA ruled he was ineligible for accepting $13,000 from a professional team in his
homeland.

Prevented from playing college ball, Radojevic entered the NBA draft and was taken with the No. 12 pick in the first round by the Toronto Raptors. Injuries cut short his NBA career. He was traded to Denver and to Milwaukee in 2001 before being cut by the Bucks.

Ohio State learned of O'Brien's payment to Radojevic through a lawsuit by a woman who said she provided housing, meals and clothes
for another Ohio State recruit from the same war-torn area, Slobodan Savovic. He played four years with the Buckeyes, including
the 1998-99 team that O'Brien led to the Final Four.

The woman is suing two other people who helped sponsor Savovic, since he was not a U.S. citizen and needed to have someone vouch
for him while he was in this country. The woman contends the sponsors did not live up to their agreement to pay her $1,000 a
month plus expenses to for Savovic's housing, food and
transportation.

The lawsuit says then-Ohio State assistant coach Paul Biancardi -- now the coach at Wright State -- also was active in handling money
for Savovic, Radojevic, Savovic's brother Predrag and another Ohio State player originally from Yugoslavia, Cobe Ocokoljic.

The woman says that Biancardi, on behalf of O'Brien, arranged for payments to the players, provided her with season tickets and
asked her to introduce players to agents. She also contends she did
much of Savovic's Ohio State homework his first three years.

Biancardi was out of town and could not be reached for comment. Wright State athletic director Mike Cusack said he had not seen any
documents, but also was trying to reach Biancardi.

Geiger said he had asked O'Brien about the lawsuit and was told by the coach it was a minor problem and would go away. On April 24,
Geiger said O'Brien told him that depositions in the lawsuit would
reveal the payment made to Radojevic.

Geiger said he had asked O'Brien whether the coach was aware he
had violated NCAA rules.

"He admitted he knew that he did," Geiger said.

O'Brien, 368-305 in 22 years as a head coach, came to Ohio State in 1997 from his alma mater, Boston College. He took over the
Buckeyes from Randy Ayers, who was fired after four consecutive losing seasons and an NCAA probation that stemmed from paying $60
to a potential recruit.

After going 8-22 in his first season with Ayers' players, O'Brien led the Buckeyes to a 27-9 record as they made it to the
national semifinals before losing 64-58 to eventual champion
Connecticut.

Last season, Ohio State finished 14-16 and missed the postseason for the first time in six years as O'Brien struggled to regain his voice after his
vocal cords were damaged during back surgery. His voice was fine Tuesday and his health was not expected to be a concern heading into the 2004-05 season.

O'Brien, who had coached the Buckeyes' since the start of the 1997-98 season, guided Ohio State to four 20-win seasons and a school record four consecutive NCAA Tournament appearances. He led the Buckeyes to the Final Four in 1999, two Big Ten regular-season co-championships (in 2000 and '02), and the 2002 Big Ten tournament championship.

Information from The Associated Press and ESPN.com senior writer Andy Katz was used in this report.